错配修复基因hMLH1甲基化与胃癌的关系

Correlation between hMLH1 and RASSF1A expression and prognosis of esophageal carcinoma

AIM: To investigate the expression of human mutL homologue 1 (hMLH1) and Ras association domain family 1A (RASSF1A) in esophageal squamous cell carcinoma (ESCC) and to analyze their prognostic value.

METHODS: The expression of hMLH1 mRNA and RASSF1A protein in 60 specimens of esophageal cancer was detected by in situ hybridization (ISH) and immunohistochemistry, respectively. The relationship of hMLH1 and RASSF1A expression with ESCC prognosis was evaluated using Cox regression model and Kaplan-Meier survival curve analysis.

RESULTS: The positive rates of hMLH1 and RASSF1A expression in esophageal carcinoma were significantly lower than those in normal esophageal tissue (41.67% vs 90.00%, 80.00% vs 100.00%; both P < 0.05). The expression of hMLH1 and RASSF1A was correlated with tumor TNM stage, invasion depth, lymph node metastasis, and tumor size (all P < 0.05), but not with patient's nationality (P > 0.05). The expression of RASSF1A was positively correlated with that of hMLH1 (r = 0.338, P < 0.01). The five-year overall survival rate for all the patients was 35% (21/60). Univariate survival analysis suggested that the five-year survival rate for patients with positive expression of RASSF1A was higher than that for patients with negative expression of RASSF1A though the difference was not significant (P > 0.05). Patients with positive expression of hMLH1 had a significantly higher survival rate compared to those with negative expression of hMLH1 (P < 0.05). Cox multivariate analysis indicated that tumor invasion depth and TNM stage were independent prognostic factors affecting survival of ESCC patients (both P < 0.05).

CONCLUSION: Both hMLH1 and RASSF1A were weakly expressed in ESCC. The expression of hMLH1 and RASSF1A was positively correlated with ESCC progression. Expression of hMLH1 and RASSF1A might be used as a prognostic parameter in ESCC patients.